How to dye your hair at home more safely
Trigger warning: This article contains information relating to increased risk of some cancers, allergic reactions and complications during pregnancy.
Synthetic hair dyes are universally popular for their convenience, cheap price and effectiveness, with up to 80% of people who identify as female believed to use hair dye in the United States, Japan, and the European Union at the start of the 21st century. Yet, despite their popularity, concerns around their safety persist. Serious allergic reactions regularly make the newspapers, and research continues to show that these products are associated with an increased risk of some cancers. We’re here to help you find out more about hair dye and how to do it safely.
Is hair dyeing safe?
There is no simple answer to this, but, in short, it appears to depend on your hair dyeing habits, your sensitivity and susceptibility to specific ingredients, your personal circumstances and genetic makeup.
Hair dyes contain ingredients that are considered to be mutagenic (capable of changing your DNA) and sensitising (capable of priming your immune system to react on repeated exposure). The concentration of these materials depends on the product format and colour – with darker dyes and permanent colours usually containing higher concentrations.
In the 1970s, research found that a high number of hair dye products on the US market were mutagenic and a number of ingredients known as aromatic amines were banned as carcinogens as a result. The aromatic amines still in use today – most commonly para-phenylenediamine (also known as PPD, 1,4-diaminobenzene or 1,4-phenylenediamine) and para-toluenediamine (also called PTD, 2,5-diaminotoluene or toluene-2,5-diamine) – are related to these carcinogens that were previously removed, meaning some experts are concerned about their long-term use. These materials provide an essential ‘base’ colour in a majority of demi-permanent and permanent colours (although aromatic amines and their derivatives can be found in semi-permanent and temporary formats too).
Research suggests that hair dye users have increased risks of non-hodgkin lymphoma, lymphocytic leukaemia, breast cancer and multiple myeloma. The risks appear to be increased for long term and/or frequent users of hair dye, users of dark and/or permanent hair dye, and for hair dye users who began colouring their hair at a young age. The research surrounding breast cancer risk has also found an increased risk for Black users of hair dye, although the reasons for this are not yet established.*
Public health experts are also concerned about rising cases of hair dye allergy. While a majority of people can colour their hair without problems, many hair dye allergens are also potent sensitisers, meaning that over time they can induce allergy in the skin. Once sensitised, allergy to a material is a life-long condition and ignored cases can lead to serious reactions.
How to dye your hair more safely
If you wish to dye your hair, there are ways to do it more safely.
- Use natural products (not just synthetic dyes with a few natural ingredients)
- Visit a professional or ask a friend to help you
- Consider using lighter colours
- Extend the time between colouring your hair
- Always patch test before using a new dye
- Wear gloves and protective clothing
- Apply a barrier cream around your hairline
- Apply the product in a well-ventilated space
- Stop using hair dye if you have any side effects
- Avoid using hair dye whilst trying to conceive or during pregnancy.
What is the safest way to dye your hair?
Professor of breast cancer surgery and researcher Professor Mokbel, who published a groundbreaking meta-analysis of breast cancer and hair dyes in 2018, shares the advice he gives to his patients: “Obviously from a health perspective, natural hair is the safest option. If someone really wants to dye their hair, I would say to use natural, even organic products. These products usually only temporarily dye the hair. There are many ingredients that we find in nature that can colour the hair, ranging from chamomile, to beetroot, to coffee, to henna, though the colours for all are limited.”
Henna has a rare affinity for the proteins in the hair, meaning it adheres to the cuticle like a varnish, allowing the natural lowlights and highlights of the hair to shine through. It will not offer uniform coverage like a permanent synthetic dye, but adds beautiful shine and body. It’s also the most effective hair dyeing material found in nature, and combined with materials like indigo in regions like the Middle East to create a range of brown and red shades. You can learn more about henna hair dye here.
How to dye your hair more safely using synthetic dyes
If you wish to dye your hair using synthetic dye, the first thing you can do is limit your contact with the product. The simplest way to do this is to have a professional colour it for you.
As Lush HairLab lead and professional colourist Daisy Evans advises, communication is key. “Having your hair dyed by a colourist means there’s far less risk of product splashing or dripping down your skin as it’s applied at a basin. Professionals can also take steps to limit your exposure to a product by using techniques like balayage and ombre, or applying the dye away from the scalp and leaving your roots alone for a natural look. I would advise making the most of your consultation and letting your colourist know that you want minimal contact with the product – they may not assume this if you do not have an allergy.”
If visiting a professional is not an option for you, there are still steps you can take to protect yourself. Lighter shades usually contain lower concentrations of aromatic amines, and you could also opt for paraphenylenediamine-free hair dyes to reduce (but not eliminate) your risk of sensitisation. You should also consider extending the intervals between colouring your hair if possible.
Another way to use synthetic hair dye more safely is to patch test before using a new product. Only around half of hair dye users in Europe take the time to patch test. Research from India suggests only 10% of the hair dye users do so. However, patch-testing is the best way to prevent yourself from having a serious allergic reaction to a product – especially one you are putting on your head. You can patch test by following the manufacturer’s instructions, but it is advisable to wait longer than the 48 hours recommended by most manufacturers.
“Induction of a contact allergy [is] initially completely asymptomatic, so not obvious that anything has happened,” explains toxicologist Dr David Basketter, a specialist in hair dye allergy. “But, you can detect that state in an individual by applying a diagnostic patch test for 48 hours. If you see a red skin reaction that occurs between 48 to around 96 hours later, the person has a developed allergy.”
Daisy adds, “In my experience, while a reaction does usually come up within 48 hours, I have had clients who reacted after this time. 96 hours is a really good window of time to ensure you are safe to go ahead. You can book in for a patch test 96 hours before even if a salon only requires a period of 48 hours.”
Asking a friend to apply for you is another way to protect yourself and limit your contact with the product. It is also advisable to wear thick gloves whenever you are applying (or removing) the dye and not to turn disposable gloves inside out and use them again – some hair dye materials are capable of penetrating through these in as little as 32 minutes.
To limit product run-off onto your scalp, face and neck, apply a barrier cream around your hairline and wear protective clothing. You should also reduce the risk of product inhalation by applying your dye in a well-ventilated space – why not use your kitchen if it’s bigger than your bathroom? Open a window, get some air flow into the space. When removing the dye, we recommend doing so over the bath or with the shower head rather than letting the product run all over your body – just make sure none gets in your eyes.
You should also stop using your product if you start to experience any side effects, even if you have used the same product for a long time without problems.
Is there a safe hair dye for allergy sufferers?
If you are allergic to one hair dye ingredient, like para-phenylenediamine (the most potent sensitiser and allergen in these products), you are likely to react to other related materials in other products. This may be because they are so similar that the immune system can’t tell them apart or because they produce the same reactive byproducts in the skin. This means that even if you know you have an allergy to para-phenylenediamine, your immune system is still likely to react to a ‘PPD-free’ product such as ‘PTD hair dye’.
Dr Basketter explains “The great majority of hair dye allergies are being caused by para-phenylenediamine or substances like para-toluenediamine that are very similar and cross react with it. You could have someone who’s only ever used para-toluenediamine in their lives, and you've got a 90% chance that if [they are allergic to it and] you patch test them with para-phenylenediamine they're going to react to it.”
Para-phenylenediamine alternatives para-toluenediamine and 2-Methoxymethyl-para-phenylenediamine (ME-PPD) are less sensitising than PPD, meaning you are less likely to become allergic to them over time. But they were designed to be alternatives from the start, not ones to swap to if you are allergic to PPD.
If you have a hair dye allergy, the safest thing to do is to stop using synthetic hair dye. If you continue, you should be vigilant with your patch tests and be aware that materials like PPD can appear under other names on an ingredients list.
Can you dye your hair when pregnant?
Hair dye use before or during pregnancy has historically been linked to increased risk of some childhood cancers or health complications such as low birth weight. Modern research in this area is staggeringly low, meaning it is not clear whether these risks have been removed or reduced in the markets that reformulated hair dyes in the 1980s. While this is a very personal decision, you may wish to avoid use of hair dye whilst trying to conceive and during pregnancy. There just isn’t the evidence to suggest it is safe. You might also prefer to choose a natural alternative like henna.
You can learn more about the risks and tips and research discussed here (as well as finding out all about the history of hair colouring and henna) in True Colours: Hair Colouring For The Curious And The Cautious, published by Lush.
*There could be a number of reasons for the increased risk of breast cancer associated with Black female users of hair dye. Black consumers are more likely to be exposed to hormone-disrupting chemicals in self-care products specifically marketed to them from a young age and these could be interacting with the hair dye or adding to an existing risk. The cause could be genetic, lifestyle-related or due to health in-equity. More research is needed.
International Agency for Research on Cancer, 2010. IARC Monographs on the Evaluation of Carcinogenic Risks to Humans. Volume 99: Some Aromatic Amines, Organic Dyes, and Related Exposures. https://publications.iarc.fr/_publications/media/download/2958/04f67887be058cb7ae62b10572bf41e37643b15c.pdf
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